Building for Longevity

Most software is built for now. For the current sprint, the current quarter, the current understanding of requirements. This is often necessary—we ship to learn, and we learn to ship better.

But some software needs to last. It needs to outlive its creators, survive changes in technology, and remain useful long after the original context has faded.

What Lasts

Looking at software that has survived decades, patterns emerge:

Clear boundaries. Systems that last have well-defined interfaces between components. When the world changes, these boundaries contain the blast radius of change.

Boring technology. The most enduring systems are built on boring, well-understood foundations. Innovation happens at the application layer, not in reinventing infrastructure.

Extensive documentation. Not just API docs, but context. Why decisions were made. What alternatives were considered. What the system is not meant to do.

Tests as specifications. When tests describe behavior rather than implementation, they become a living contract that guides evolution.

The Humility of Longevity

Building for longevity requires humility. It means acknowledging that we don't know everything—that future maintainers will have insights we lack. It means making code that's easy to change, not just easy to write.

"Always code as if the person who ends up maintaining your code is a violent psychopath who knows where you live."

This isn't paranoia. It's respect for the future.